In the recent years, the VDCP (Video Disk Communication Protocol) protocol has been adopted as an industry standard control protocol for program data recording/playback in video servers used by video broadcasters. Typically, a control signal corresponding to the VDCP protocol is sent from a video server controller to a video server to control recording/playback of content data (broadcast program data).
However, sometimes regular program broadcasting might be interrupted by the broadcast station to insert a special program not originally planned. When a special program is inserted, it is desirable that playback of the regular program be restarted from the location just before insertion point of the special program. For this to happen, an instruction is sent to the video server requesting the name of the content data corresponding to the interrupted regular program and also a request for holding of the time code (TC-HOLD request) of the interruption point. It is then necessary to provide a RECUE request so that playback waits at the interrupted site after the end of the special program.
Unfortunately, the TC-HOLD request and RECUE request cannot be realized with the standard commands of the VDCP protocol. Consequently, after the interrupting program has finished, to restart playback of the regular program from the position just before the interruption, it is necessary for the video server controller and the video server to communicate using SECNET or some other independent control protocol, or alternatively to extend the VDCP protocol to provide an independent command for carrying out communication between the video server controller and the video server.